Flasher switch



March 1961 w. J. LESSNER FLASHER SWITCH 2 Sheets-Sheet 1 Filed Nov. 5, 1958 IN VENTOR. MZZ/AM J (6554/6? March 28, 1961 w. J. LESSNER FLASHER SWITCH 2 Sheets-Sheet 2 Filed Nov. 5, 1958 INVENTOR. M/ZMM .Z zassA/se United States Patent FLASHER SWITCH William J. Lessner, Cleveland, Ohio, assignor to Benjamin S. Gerson, Shaker Heights, Ohio Filed Nov. 5, 1958, Ser. No. 772,117

6 Claims. (Cl. 200-113) This invention relates broadly to thermal switches, and more specifically to improvements in flasher switches for automobile turn indicators.

7 One of the objects of the invention is to provide a flasher switch that will produce a sharp audible click upon actuation of the snap action contact element therein.

Another object of the invention is to provide parts for the switch which are susceptible of manufacture with liberal tolerances, yet will not impede the operation of the switch after assembly.

Another object of the invention is to provide a switch that embodies fewer parts than similar switches made to accomplish the same or similar result.

Another object of the invention is to provide a switch which is economic of manufacture, eflicient of operation, and susceptible of assembly with ease and dispatch.

Other objects and advantages more or less ancillary to the foregoing, and the manner in which all the various objects are realized, will appear in the following description, which considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.

Referring to the drawingsr Fig. 1 is a front elevational view of the improved flasher switch;

Fig. 2 is a side view thereof;

Fig. 3 is a front elevational view of a modified form of the switch;

Fig. 4 is a side elevational view thereof;

Fig. 5 is a transverse sectional view, taken on a plane, indicated by the line 55 in Fig. 2;

Figs. 6 and 7 are modified forms of the snap action diaphragm;

Fig. 8 is a front elevational view of another modified form of the switch diaphragm;

Fig. 9 is a vertical sectional view thereof;

Fig. 10 is a front elevational view of another modified form of the diaphragm;

Fig. 11 is a transverse sectional view thereof;

Fig. 12 is a wiring diagram of the turn signal circuit; and

Fig. 13 is a wiring diagram of an alternate circuit.

Referring first to the preferred embodiment illustrated in Fig. 1, the switch comprises a circular base 10 formed of an electrical insulating material, such as Bakelite, and preferably about one and three-eighths of an inch in diameter which receives and supports a cylindrical hood or cup 11. The base has a metallic angle bracket 12 secured to the center thereof, embodying a contact point 13 pressed or riveted in the upper portion thereof. A strip of thin insulation 14 overlies the upper face of the lower leg 15 of the angle bracket 12 and is folded over the upper face of an arm 16 having a protruding arcuate end portion 17 that supports one end of a thermal expansive resistance wire 18. A thin metallic plate 19 having a body including a margin surrounding a central portion in the form of a concave-convex area or cupped diaphragm 20 pressed in the center thereof, and further formed with a base flange 21, is mounted on the top of the insulation strip 14 on the bar 16. A second angle bracket 22 having an arcuate recess in the vertical leg thereof and a central vertical arm 23 is mounted on the insulating strip 14 on the face of the base flange 21 of the plate 19. The arm 23 is provided with a contact point 25 disposed in aligned relation with a contact point 26 in the center of the diaphragm 2t and the bracket 22 is insulated from the plate 19 by the upper end of the insulating strip 14, save for an area adjacent an opening 28 in the strip disposed in confronting relation with the contact point 26 in the diaphragm. The other end of the resistance wire 13 is aflixed to a flange 29 adjacent the top of the plate 19, and the side arms 30, defined by the arcuate recess in the bracket 22, support the vertical edges of the plate 19 and serve as a fulcrum member when the wire 13 is tensioned in its normal operative position. As is seen in Figures 1 and 2, the ends of these arms have limited area contacts with the margins of the plate on opposite sides of the central portion thereof. When the wire is tensioned, the plate is flexed about those contacts as fulcrums and is held in this stressed position while the wire is cold. When the Wire is heated during the operative cycle of the switch, it will elongate, relieve the tension thereon, and the plate will snap away from the contact 13 in the bracket 12 and engage the contact point 25, thus closing the circuit to the panel light. As the contact 26 leaves the contact 13, the electric circuit to the wire 18 is broken, and as the wire cools and consequently shortens, the initial tensive strain thereon Will again be imposed on the plate 19, returning contact 26 to its original bearing on contact 13 and again flexing the plate about the fulcrum contacts.

A rivet 33 disposed in the center of the base 10 supports the leg 15 of the angle bracket 12, the arm 16, the angle bracket 22 and the plate 19, all of which are insulated from each other and from the rivet 33 by a tubular insulating bushing 34. The arm 16 is provided with a right angle branch 35 electrically connected to the rivet 32 and the prong 31.

In operation, current flows through the prong 31, the rivet 32, the branch 35 of the arm 1.6, the wire 18, the plate 19, through the contact point 26 to the contact 13, thence through the angle bracket 12, the leg 15, thence the rivet 36 and prong 37.

As the wire 18 is heated, it will be elongated and the tensive effort on the plate 1.9 will be relaxed and cause the diaphragm 20 to snap rearwardly breaking the electrical connection between contact points 26 and 13. The current will then flow through the contact points 26 and 25, through the bracket 22, thence through a wire 38 soldered thereon and to a rivet 39 and prong bracket 40.

Figs. 3 and 4 illustrate a modified form of the snap action switch plate. In this form, the switch comprises a thin metallic plate formed with a central dished diaphragm 101 and a flanged base 162. The top of the plate 100 is connected to a thermal expansive resistance wire 103 secured at its lower end to an arm 104 insulated from the plate 100 and an angle bracket 195 by an insulating strip 106. The side of the arm 104 is provided with a lateral tongue 107 (Fig. 4) which is secured to the base 10 by a rivet 103 that also supports a contact prong 109. The base 10 further carries the angle bracket which is secured by a rivet 119 that supports a contact prong 111. A second angle bracket 112 is mounted on the upper face of the flanged base 102 cf the plate 100. The plate 112 is similar to the bracket 22 save only that the vertical arm 23 and contact point 25 thereof are omitted. The center of the diaphragm and the upper portion of the bracket 105 are provided with aligned contact pins 113 and 114, respectively. In this embodiment, as in the former case, the wire 103 is tensioned during assembly so that the plate is flexed about the contact at the ends of the plate 11?. and the diaphragm contact pin 113 is engaged with the contact pin 14. The wire, when heated and elon gated, will permit a snap action of the dished diaphragm Till and break the circuit through the wire until it cools and reestablishes the circuit. in this switch, the electric circuit flows through the connection shown in Fig. 13 wherein the contact 25 is eliminated and the line 87 is connected to the line 90 for the front and rear lights and d5.

As illustrated in Fig. 6, the diaphragm 20 may be formed from a plate 19 having spacedradial grooves 60 pressed therein to deform the central portion thereof and cause the plate to buckle and produce a snap action when a tensive effort is imposed thereon.

As shown in Fig. 7, spaced concentric circular ribs 61 are pressed in the plate 19 to effect a similar snap action of the central portion of the diaphragm. The ribs may be broken, or of any configuration other than shown, as long as the embossed portion produces a resultant force of stress in one direction. The diaphragm may be made of beryllium copper, though tempered steel has been found entirely satisfactory and more economic.

lnthe modified form illustrated in Figs. 8 and 9, the plate 19 is formed with legs 62 on the opposite sides thereof and kerfs 63 terminating adjacent the depressed cupper diaphragm 64 which define a central depending arm 65. The center of the diaphragm 64 is provided with a contact point 66, either pressed therein or formed by a rivet. The arm 65 has a similar contact point 67 adjacent its lower end in the medial axis thereof. As a snap action of the diaphragm 64 occurs, the arm 65 will fulcrum adjacent the diaphragm and effect the movement of the arm in an opposite direction and into abutting contact with a connection, such as the bracket 23.

Figs. and 11 illustrate a further modified form of the diaphragm plate 19. In this embodiment, the diaphragm 20 is provided with a pair of contact points 70 and 71, the point 71 being connected to a flexible wire '73 and insulated from the diaphragm by a bushing 72, and the point 7%) being in electrical contact with the diaphragm. The contact 70 engages an electric contact on a part similar to the bracket 12, and the contact 71 is simultaneously engaged with a second terminal when the circuit is closed.

The wiring diagram shown in Fig. 13 illustrates a battery 80, one of the terminals thereof being connected through a line 31 to ground. A second line 82 from the battery leads to a switch 83 on the steering column that controls the operation of the direction indicator, and a line leads to a terminal in the improved switch that is coupled with the resistance wire 18. The contacts 13 and 26 are normally closed, the tensive effort on the wire being adjusted during assembly so the diaphragm contact point 26 on the diaphragm 20 is engaged with the contact E3 on the angle bracket 12. The contact point 13 is also connected to a line that leads to the automobile front and rear lights 84 and 85. The lights are connected to ground through line 86. The contact point 25 in the second bracket 22 is connected through a wire 87 to the panel indicator light 88 which is also grounded through a line 89.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to be understood that the specific terminology is not intended to be restrictive or confining, and that various rearrangements of parts and modifications of detail may be resorted to without departing from the scope or sp-iritof the invention as herein claimed.

What is claimed is:

1. An automobile turn indicator switch comprising a thin sheet metal plate having a fiat, fiangeless, flexible body including a central portion surrounded by a margin, 2. fulcrum member having limited area contacts with the margin on the opposite sides of said central portion and about which contacts the margin may be flexed to flexed position with resultant creation of stress in the central portion, an electrical contact near the center of said portion, a conductor having an electrical contact engageable with the contact of said portion when said plate is in flexed position, an electrically conductive resistance wire connected to the margin of said plate and extending at an angle to the plane of the plate and substantially along a diameter of said central portion, said wire being tensioned, when cold, and holding said plate in flexed position, and means for supportingsaid plate, fulcrum member and wire in assembled position.

2. An automobile turn indicator switch comprising a base, a thin sheet metal plate connected at one end to said base and having a flat, flangeless, flexible body including a central portion surrounded by a. margin, 21 fulcrum member having limited areacontacts with the margin on the opposite sides of said central portion and about which contacts the plate may be flexed to flexed position with resultant creation of stress in said portion, an electrical contact near the center of said portion, a conductor connected to the base and having an electrical contact engageable with the contact of. said central portion when said plate is in flexed position, and electrically conducting resistance wire connected to the margin of said plate and extending at an angle to the plane of the plate and substantially along a diameter of said central portion, said wire being tensioned, when cold, and holding said plate in flexed position.

3. The combination of elements set forth in claim 1 in which the central portion of the plate is a concaveconvex disc-shaped area.

4. The combination of elements set forth in claim 1 in which the said central portion is provided with a plurality of spaced radial grooves. V

5. The combination of elements set forth in claim 1 in which the said central portion is provided with spaced circumferential ribs.

6. The combination of elements set forth in claim 1 in which the said central portion is provided with a central depending arm engageable at its free end with an abutment on which the arm may fulcrum when the plate is flexed.

References Cited in the file of this patent UNITED STATES PATENTS 2,166,238 Davis July 18, 1939 2,415,473 Dougherty Feb. 11, 1947 2,692,981 Hollins Oct. 26, 1954 2,806,918 Lautzenhiser Sept. 17, 1%7 2,806,921 Welsh Sept. 17, 1957 2,820,120 Flatt et al. Jan. 14, 1958 

